What does the let keyword allow in JavaScript?

The let keyword in JavaScript introduces block scope to variable declarations. This means that when a variable is declared using let within a block (such as inside an if statement or a for loop), that variable is only accessible within that block and is not available outside of it. This promotes cleaner code by avoiding variable hoisting issues and helps prevent unintended interactions between variables in different scopes.

For example, if you declare a variable using let inside a loop, that variable will not be accessible after the loop ends, unlike a variable declared with var, which has function scope and can lead to potential conflicts and harder-to-debug scenarios. Since block scoping is a core feature of how let operates, it promotes better variable management and reduces the chances of errors related to variable scoping.

The other options, while relevant to variable scope and declaration, do not accurately describe the function of let. Global scope access refers to variables that are accessible throughout an entire program, function scope involves visibility only within the function itself, and lexical scoping pertains to how variable scope is determined based on the location of the variable in the nested structure, which is not exclusive to let. Therefore, the correct understanding rests on the block scope feature that let provides.